Updated 3.27PM: Jim Burdett is welcoming news the 39-year-old's convictions for the rape and murder of his sister, Susan,  have been quashed.

"For me there was a sense of satisfaction that an injustice has been revealed."

He says the allegations against Teina Pora simply didn't stack up.

AUDIO: Jim Burdett - "Too many things didn't add up"

AUDIO: Maori Party co-leader Marama Fox on the Teina Pora verdict

"Too many things didn't add up. It seemed inconceivable that Teina Pora and Malcolm Rewa could have been in the same place."

Private investigator Tim McKinnel says the Pora legal team wants to see justice for the Burdett family.

"If there isn't a retrial then the question will arise as to what evidence exists and who that might point to."

Maori Party co-leader Te Ururoa Flavell says it's a great day for those who stood by Mr Pora, never believing he killed Susan Burdett in 1992.

"It just so happened that Teina Pora had those people who believed in him and did the research and had the contacts which allowed the case to be taken up in a fairly aggressive way."

Flavell believes the killer now has to be found.

Retrial possible

Police will consult with Crown Law on any submission about whether Teina Pora should face a retrial.

The Privy Council has quashed Mr Pora's convictions for the 1992 rape and murder of Susan Burdett.

MORE: Pora's convictions quashed

AUDIO: Pora's lawyer Jonathan Krebs discusses the next step

It's also asked for submissions over the next four weeks, on whether there should be a third trial.

Assistant Commissioner Malcolm Burgess says police will take time to fully consider the judgement.

He's also noting the Privy Council's comment, which says it's clear that none of the police officers exerted pressure on Mr Pora in relation to his confession.

Teina Pora's legal team says the potential for compensation has crossed its mind.

Lawyer Jonathan Krebs says if it's decided there will be no retrial, then Teina Pora is in the position of an innocent man.

"The issue of his 21 years actually in custody, 22 years in restrictive custody of some sort or another, has to be called into question."

Otago University's Marcelo Rodriguez-Ferrere says if Mr Pora faces a retrial, he will have to prove exceptional circumstances to receive compensation.

"If the conviction is quashed without a retrial, that threshold simply goes down to whether he is innocent."

Teina Pora's supporters are welcoming the Privy Council decision.

Private investigator Tim McKinnel says they feel pretty good about how things have played out.

"A big smile broke out on his face and I think it's fair to say that those of us who were with him welled up with tears. It was a pretty emotional time."

Calls for new review body

There are renewed calls for a new legal body to review possible miscarriages of justice.

Canterbury University Dean of Law Chris Gallavin says Teina Pora decision is further evidence New Zealand needs a Criminal Cases Review Panel.

He says the current appeal system is a good mechanism, but it's not adequate by itself.

"It really does reflect that in some cases the courts are ill equipped to deal with some of the complexities."

Chris Gallavin says the government would also probably save money in establishing a panel, because high-profile defeats are extremely expensive.

Jonathan Krebs says panels in other countries have powers, the courts don't.

"I think the time is very ripe now for such a body to be reconsidered for New Zealand, and I expect there will be a lot of discussion about that."

Jonathan Krebs says the last three cases taken to the Privy Council have resulted in convictions being quashed, and much could have been saved had there been a commission in place

Otago University's Marcelo Rodriguez-Ferrere says it wouldn't be neccessary in New Zealand.

"There's nothing stopping, as many prisoners do, applying for the Royal Perogative of Mercy."

The Justice Minister is pouring cold water on the suggestion New Zealand needs a Criminal Cases Review Panel.

Amy Adams says the justice system already has a highly regarded, robust appeal process.

She says 99.9% of convictions are upheld, and the few that are overturned demonstrate the system works as it should.

The minister says an independent body to deal with miscarriage of justice applications would just replicate the process already available through the Royal Prerogative of Mercy.

Confession 'unreliable'

Expert evidence brought by Teina Pora's defence has led to his convictions being quashed by the Privy Council.

The Privy Council's decision means his parole conditions now fall away.

Lord Kerr says the board has accepted expert evidence which said Pora suffered from a form of Foetal Alcohol Spectrum Disorder... casting doubt on the reliability of his confessions.

"Having admitted those reports, the Board concluded that the opinions of these experts, called seriously into question whether these confessions could be regarded as reliable."

End of an era

The Teina Pora case could mark an important milestone in our legal history.

It's likely to be the last New Zealand case heard by the Privy Council in London, with court decisions after 2003 being heard by the Supreme Court.

TVNZ UK correspondent Jessica Mutch says the case felt like the end of an era in our relationship with Britain.

"Sitting in the courtroom you could see the New Zealand flag draped in the corner, and thinking it could be the last time."

Teina Pora timeline

1992, March 23: Susan Burdett raped and murdered in her home in south Auckland.

1993, March 23: Teina Pora charged with burglary, sexual violation and murder.

1994, June: Pora convicted as a party to the rape and murder on the basis of confessions he made. Sentenced to life in prison.

1996, May: Rewa arrested after attacking a young woman in the inner Auckland suburb of Remuera, DNA from Rewa's father found to match semen from Burdett crimescene.

1998: Rewa eventually convicted of the rape of 27 women, including Ms Burdett but two juries fail to reach a verdict on murder.

1999: Court of Appeal quashed Pora's convictions as a result of the DNA evidence implicating Rewa and evidence that Rewa acted alone.

2000, June: Pora was again convicted at his retrial, based on his confessions and witnesses, some of whom it later emerged were paid. His appeal to the Court of Appeal was dismissed.

2009, September: Private investigator and former police detective Tim McKinnel visits Pora in prison and is given permission to make inquires on Pora's behalf.

2011, September: Pora team file notice of application for the Royal Prerogative of Mercy but two years later are granted an appeal to the Privy Council.

2012, May: Police's criminal profiling expert goes public in Herald with view Pora not involved; Pora's team sue police claiming it is unlawfully withholding evidence, Ms Burdett's brother says Pora is innocent.

2013, February: It is revealed police paid some prosecution witnesses.

2013, August: The Police Association call for an independent inquiry into Pora's convictions.

2014, April: Pora granted parole at his 13th appearance before the board and after spending 21 years in jail.

2014, November: Five-member Privy Council panel hears appeal.

2015, March 3: Privy Council quash convictions.